Traditionally, models and methods for the analysis of the functional correctness of reactive systems and those for the analysis of their performance (and dependability) aspects have been studied by different research communities. However, in modern systems the difference between their functional features and their performance properties has become blurred. During the last decade, this trend has motivated and increased interest in combining insights from the field of formal methods, traditionally focussed on functionality, with techniques from performance modeling and analysis. The 11 chapters in this book present the state of the art of research and tool development for the promising integrated approach towards modeling and analysis of functional and performance aspects of reactive systems.